FLORENCE, Italy (Reuters) — American
student Amanda Knox and her former Italian boyfriend Raffaele Sollecito
were found guilty on Thursday for the second time of the 2007 murder of
Briton Meredith Kercher, in a retrial that reversed an earlier appeal
judgment.

The verdict, after 12 hours of deliberations, confirmed Knox and
Sollecito's original 2009 conviction. Knox's sentence was increased
to 28 years and six months and Sollecito was sentenced to 25 years.
Knox did not attend the retrial, however, having gone home to the
United States after the previous appeal.

"I am frightened and saddened by this unjust verdict. Having been
found innocent before, I expected better from the Italian justice
system," Knox said in a statement.

Sollecito's lawyer Giulia Bongiorno confirmed that her client would
appeal to Italy's highest court, and Knox's lawyer Carlo Dalla
Vedova said he was "stunned". The court will publish the reasons for
its verdict in 90 days.

For Kercher's family, who had pushed to have the appeal verdict
overturned, the reaction was equally raw.

"We didn't know what to expect. We are still in shock," said
Stephanie Kercher, Meredith's sister, after the ruling was read.

If final appeals are heard, neither Knox nor Sollecito, who was
banned from leaving Italy, would face arrest or jail time until a
final verdict by the highest court.

Knox, who is in the United States and would have to be extradited to
serve her sentence, attacked the "overzealous and intransigent
prosecution" and "prejudiced and narrow-minded investigation" and
said she had been wrongfully prosecuted.

Gabriele Giambrone, managing partner of Anglo-Italian law firm
Giambrone Law, said it was "very unlikely" Knox would be extradited
to serve her sentence.

"The U.S. will do everything to protect their own citizens, they
will mount every challenge possible, so I don't think she'll serve
any time in an Italian jail," said Giambrone, who is not involved in
the case.

The U.S. State Department declined comment on the matter, given
"that that there is room for appeal in this case."

Legal experts estimate the case could continue until the end of
2015, although it could be brought forward if fast-tracked.

INCONSISTENCIES

Kercher, 21, was found stabbed to death in her bedroom in the
apartment she shared with Knox in the Umbrian city of Perugia in
2007, where the two were students.

Investigators quickly pointed to Knox and Sollecito as suspects,
building a narrative that the two killed Kercher in a sex game gone
awry. Both were convicted in 2009 and spent four years in prison.

They were cleared on appeal, but Italy's highest court last year
quashed that verdict due to "inconsistencies" and ordered a repeat
of the appeal trial. It was this trial that concluded on Thursday.

From the start, the case, one of the highest-profile murder trials
in recent Italian history, has been played out as much in the media
as in court, with bloggers and journalists sifting through evidence
and weighing in for or against Knox and Sollecito.

Initially portrayed as a sex-obsessed party girl, Knox has seen a
steady transformation of her image, helped by a sophisticated
publicity machine that has portrayed her as a victim of a faulty
justice system.

Knox's lawyers have made stinging criticisms of police procedures,
the handling of evidence from the crime scene and the conduct of the
prosecution.

They argued that only one person is guilty of the murder: Ivory
Coast-born Rudy Guede, who is serving a 16-year sentence for
sexually assaulting and stabbing Kercher.

His trial found that he did not act alone because of the number and
variety of Kercher's more than 40 wounds.

While the initial case had argued that Knox and Sollecito killed
Kercher in a sex game gone awry, the prosecution has moved away from
this interpretation in the current appeal.

The retrial has focused on a re-examination of DNA evidence.

In closing defense arguments, Sollecito's lawyer argued that a trace
of his client's DNA on a metal hook on Kercher's bra clasp was there
due to contamination, because it was not collected from the crime
scene until more than a month after the murder and was repeatedly
touched.

The defense and prosecution contest whether Kercher's DNA was on the
blade of a kitchen knife from Sollecito's apartment, which had been
used by Knox.